For mysterious, quantum-mechanical reasons, the screws that hold handles and doorknobs always eventually work loose. A few drops of thread-locking compound will permanently fix the problem, yet still allow you to remove the screw with ordinary tools if you need to later. A heavier-duty variety is also available for large bolts and machinery.
Keep those spiders outside where they belong! I fill a 4 ounce glass spray bottle with water and add about 10 drops of doTERRA peppermint oil and spray it along the edges of my front door, along the frame, etc. once a week or so. It not only smells great it keeps these guys out! I don't want to kill them and this is a natural, harmless alternative to pesticides.